This invention relates to cable support systems, and methods of construction and utilization thereof, and more particularly to a support system for electrical cables comprising a series of elongate racks connected together end-to-end, and to a rack per se.
The system of this invention is in the same general class as the cable support system shown in U.S. Pat. No. 2,891,750 entitled Cable Supporting System comprising racks of wire construction connected together end-to-end by having the wires constituting the lower side members or stringers and the upper wire members or stringers of each rack formed with eyes receiving bolts threaded in nuts welded under the lower eyes.
Among the several objects of this invention may be noted the provision of a support for electrical cables of the same general class comprising a series of racks connected together end-to-end, and the provision of racks for assembly thereof to constitute the support, with the racks and the system constructed from the racks of relatively light weight, the racks being formed of relatively light weight components which are economical to provide and the racks being relatively easy to assemble end-to-end for minimizing the cost of assembly; and the provision of such a light-weight support and light-weight racks thereof adapted adequately to support the load of a plurality of cables without undue deflection and adapted for installation with quick and easy assembly of racks end-to-end; the provision of such a support adapted for supporting cable (such as fire alarm cable) with the cable protected; the provision of a method of efficiently and economically constructing a support utilizing such racks with the support having a change in direction (a bend) for change in direction of cable supported thereby; and the provision of a method of supporting electrical cable with cable laid in cable-supporting racks and with cable enclosed in a component of the racks for dual utilization of the racks.
In general, the invention involves a support for electrical cable comprising a series of elongate racks connected together end-to-end, each rack comprising a pair of elongate lower members extending in parallel spaced relation longitudinally with respect to the rack at opposite sides thereof and cross-members extending transversely with respect to the rack between the lower longitudinal members spaced at intervals along the length of the rack and holding the lower members in their said parallel spaced relation, the cross-members serving to support cable laid thereon. Each rack further comprises a pair of elongate upper members extending in parallel spaced relation longitudinally with respect to the rack above the lower members, and side members extending between the lower and upper longitudinal members spaced at intervals along the length of the rack and holding said upper members in parallel relation to the lower members spaced above the lower members. Each of said lower and upper longitudinal members comprises a metal tube of circular cross-section. Each of said cross-members is an elongate sheet metal member having a reach extending between the lower tubes formed so as to be stiffened against bending and having formations at each end thereof with a part-circular contour fitted on and secured to the lower longitudinal members. The side members and upper tubes form railings at opposite sides of the rack for retaining cable on the cross-members. The racks are interconnected end-to-end by means of couplings which couple together meeting ends of at least some of the tubes of successive racks in the series. The invention also involves the rack per se.
The aforesaid method of constructing a support generally involves the placement of a first and a second rack of the support in coplanar position with the first extending in a first direction and the second extending in a second direction diverging from the first, each rack comprising a pair of elongate lower members extending in parallel spaced relation longitudinally with respect to the rack at opposite sides thereof; cross-members extending transversely with respect to the rack between said lower longitudinal members spaced at intervals along the length of the rack and holding said lower members in said parallel spaced relation, said cross-members serving to support cable laid thereon, a pair of elongate upper members extending in parallel spaced relation longitudinally with respect to the rack above the said lower members, side members extending between the lower and upper longitudinal members spaced at intervals along the length of the rack and holding said upper members in parallel relation to the lower members spaced above the lower members; each of said lower and upper longitudinal members comprising a metal tube, the ends of the tubes of the first rack at one end thereof lying generally in a first plane transverse to the first rack and the ends of the tubes of the second rack at one end thereof lying generally in a second plane transverse to the second rack, said planes intersecting at said angle, bending metal tubes of the same cross-section as the tubes of the racks to form tubular connections between said ends of at least two of the tubes of said first and second racks, coupling the ends of the tubular connections to said ends of the tubes of said first and second racks which they are to interconnect.
The aforesaid method of supporting electrical cable generally involves preparing a support comprising a series of elongate racks each comprising a pair of elongate lower members extending in parallel spaced relation longitudinally with respect to the rack at opposite sides thereof; cross-members extending transversely with respect to the rack between said lower longitudinal members spaced at intervals along the length of the rack and holding said lower members in said parallel spaced relation, said cross-members serving to support cable laid thereon, a pair of elongate upper members extending in parallel spaced relation longitudinally with respect to the rack above the said lower members, side members extending between the lower and upper longitudinal members spaced at intervals along the length of the rack and holding said upper members in parallel relation to the lower members spaced above the lower members; each of said lower and upper longitudinal members comprising a metal tube, the racks being interconnected in end-to-end relation by couplings which couple together meeting ends of certain tubes, the couplings being free of obstruction to the bores of the tubes, the method comprising laying cable on the cross-members of the racks, and inserting cable in one or more of the coupled-together tubes which extends throughout the length of the support, the inserted cable extending longitudinally therethrough as permitted by nonobstruction of the bores of the tubes by the couplings.
Other objects and features will be in part apparent and in part pointed out hereinafter.